prime_path.py

class Node:
	Node left
	Node right
	int data
	int prime_depth # extra space
	int path_size # extra space

global max_path_size = -1
global max_path_node = None

def calculate_max_path_node(root):
	calculate_max_path_node(root.left)
	calculate_max_path_node(root.right)
	if data is not prime:
		root.prime_depth = 0
		root.path_size = 0
	else:
		root.prime_depth = 1 + max(root.left.prime_depth, root.right.prime_depth)
		root.path_size = 1 + root.left.prime_depth + root.right.prime_depth
	if root.path_size > max_path_size:
		max_path_size = root.path_size
		max_path_node = root